Heat transfer element



Feb. 5, 1952 a. sPlETH HEAT TRANSFER ELEMENT 2 Sl-IEETS-SHEET 1 Filed Nov. 22, 1948 Feb. 5, 1952 B. sPlErH HEAT TRANSFER ELEMENT {SHEETS-SHEET 2 Filed Nov. 22, 1948 Patented Feb. 5, 1952 2,584,239 HEAT TRANSFER ELEMENT Benjamin Spieth, Racine, M Wis., assignor to Modine Manufacturing Company, Racine, Wis., a corporation of Wisconsin Application November 22, 1948, Serial No. 61,363

14 claims. (cl. 257-46) This invention relates generally to heat transfer elements, and more particularly to a heat transfer element capable of use in convection heaters or the like, in a system known to the trade as a one pipe steam system. Another embodiment of my invention is disclosed vand claimed in my co-pending application Serial No.

60,569, filed November 17, 1948, now Patent No.'

The one pipe steam system is probably the simplest oi heating systems in that, as its name implies, only one pipe is required to transmit steam from the boiler to the convection heater and return the condensate from the convection heater back to the boiler.

There are certain inherent faults in a one pipe steam system which may cause improper heating and .objectionable noises, and the present invention concerns a novel construction to be incorporated into they heat transfer unit of the steamtype convection heater which will eliminate the faults ordinarily associated with a one pipe steam system.

The present invention is an improvement over heat transfer elements as, for example, those disclosed in United States Letters Patent No. 2,056,263, issued on October 6, 1936, to Morris Ehrlich, and while utilizing similar principles oi operation, has among its objects a much more simple construction, smaller in size, less expensive to manufacture, and more efficient in operation than previous devices.

Another object of the invention is the production of such a heat transfer element in which the characteristics thereof may be readily and easily altered to meet varied conditions, and in which the supply piping may be utilized in conjunction with the device, thus eliminating the use of a header member of greater vertical or other dimensions than the corresponding dimensions of the heat transfer portion of the device.

Many other objects and advantages of the present invention will be apparent to those skilled in the art from the disclosure herein given.

In the drawings wherein like reference characters indicate like or corresponding parts:

Fig. l is a plan partly broken out of a heat transfer element embodying a simple form of the present invention.

Fig. 2 is a sectional view taken approximately on the line 2-2 of Figi.

Fig. 3 is a sectional view taken approximately on the line 3-3 of Fig. 1; and

Fig. 4 is a detailed vertical central section of a slightly modied form of water column or trap?.

The invention illustrated contemplates a structure for maintaining a uni-directional steam flow through a heat transfer element, connected in a one pipe lsteam heating system, by creating a wa'- ter pressure head that will oppose a counter-- steam new in the exchanger While ll am 'aware 2 that devices for producing such a result have been heretofore employed, as evidenced, for example, by the Ehrlich patent heretofore referred'to, such devices have been extremely bulky and heavy, resulting in a cumbersome unit, these disadvanf tages having resulted from the use of a header member or complete radiator, etc., which had incorporated, as an integral part thereof, the water trap elements employed to create the desired water pressure head.

In contrast with such construction, the present invention accomplishes the desired results with the use of a very small, simple header member in conjunction with a tubular trap member whichv may extend down .into the steam inlet piping whereby the overall dimensions of the header member may remain constantv regardless of the particular means for producing the amount of pressure head desired. .Y

Referring to the drawings, and particularlyto Figs. l, 2, and 3, I indicates generally a heat transfer element having an inlet header member 2, and a second hollow header member 3 connected by tubes 4 and 5, the latter, in the construction illustrated, being provided with a plu'- rality of transversely extending fins 6. Secured to the side edges ,'I of the fins 6 are respective side plates 8, the ends of the tubes Il and 5 ade jacent the header 3 being carried by 'an end plate 9 secured to the plates 8 with the adjacent end of the device being supported by a bracket member II, having upwardly extending legs I2 secured by any suitable means, such as spot welding, to the respective side plates 8. The opposite end of the device is carried by a bracket I3 having upwardly extending legs I4 similarly secured to the VVadja'zentl end plates 8. The inlet header 2 is illustrated as being constructed in the form of VVa casting or the like, the lower end of which terminates in a pipe connection or boss I5 having a threaded bore I5 into which may be threaded the upper end of the steam supply pipe Positioned above and substantially axially aligned with the pipe I6 and bore IIS' is a com bined condensate return and air chamber I1y having Va bore I8 therein communicating with the adjacent end of the tubel, The upper end of the header 2 is provided withv a bore I9 axially aligned with the chamber I'I and pipe I6 and threaded to receive a pipezl having a thermostatic 4air release valve 22 mounted on its upper end. The header 2 is also provided with a bore 23 axially aligned and communicating with the chamber I'l and bore I5.

Positioned in the bore 23 and secured to the header 2 by threads, as illustrated, or other suitable means, is a tubular trap 24, the open end 25 oi' which is rieversely curved, as indicated at 26. The ends of the tubes 5 adjacent to header2 are 'bent inwardly and downwardly withth'e" free ends 2l 'thereof inserted into respective bores 28 in the header 2, .thus communicating directly with the supply pipe I6. The headers, tubes, fins, side plates, and brackets may be suitably assembled and bonded together by soldering, or the like, to provide an integral structure.

In operation, steam may enter the header i2, passing through the tubes to the header 3, the condensate returning to the headerk 2 through the tube 4 into the chamber "I 'I' and tubular trap 24. Condensate will thus collect in the reverse bend of the trap 24 until the level in both legs thereof reaches the mouth 29 of the trap, the condensate then flowing into the pipe I6 and returning to the boiler. `It will be apparent that the condensate in the reverse bend of the trap 2.4 -creates Aa pressure head that will resist the entrance ofrsteam through the member 24 to.

the chamber I'I and the tube 4, thereby promoting the owof steam through the tubes 5 and header. 3 gwith the return owA through tube 4 into chamber I1 and trap 24. As a result of this action, a uni-directional steam flow is maintained. Any-air in thesystem will pass through the device and collect in the chamber I1 and pipe 2|, from which-it may be released through the thermostatic airvalve 22. It will be-noted that 'the effective pressure head resisting the entrance` of steam into the trap 24, chamber I1, andjtube 4 is equivalent to'a column of condensate twice the height of the upwardly extending end 25 of the trapmember 24. Such pressure head may be readily increased, if desired, by employing a longer trap member and l providing a longer upwardly extending end portionV 25, thereby increasing the total condensate column yproducing the pressure head. Should the seal produced by the trap 24 blow as a result of .relatively high steam pressures in the supply Vpipe I6 entering a cold heat transfer element,'unidirectional steam flow will be readily established upon the filling of the trap 24 with condensate.

Y It will be noted that in the present construction the maximum available pressure head derived from the trap member 24 is limited only byL the vertical length of the steam supply pipe I6, and,.with a suiciently long supply pipe, the trap vmember 24 .may be 4of any suitable length to. achieve the desired results.

Illustrated in Fig. 4is a `modified form of trap member 24' constructed in the form of a Vertically. extending tube 3|, the lower end of which is closed, as indicated at 32. Secured to the lower` endof the tube 3| is a tubular member 25' concentrically arranged with respect to and of larger diameter than the tube 3|, the member Y25 being secured to the tube 3|at 33,. The tube 3| is provided with a small hole 34 adjacent the bottom of the member 25' whereby .condensate is` free to pass from the bottom of the tube-3| into the space between the latter and the member 25' until the condensate level in both the tube and the intermediate space reachesthe top `of the, member 25', at which,l time it will now over the upper edges thereof into the pipe I6. It ywill be apparent that lthe operation of the trap illustrated in Fig. 4 is similar to the trap member 24 with the `pressure head produced being dependent upon thevertical distance between the upper edges of the member 25 and the hole 34 in the tube 3|. 'It'will be noted that the header 2 is of relatively s'imple construction with the bores I5', I9,

and 23all'being axially aligned for easy castinggrmachining, and assembling.Y It will also be noted that the employment of the downwardly extending tubular trap member 24 or 24' permits the employment of the supply pipe I5 as a housing for the trap member, resulting in a reduction in the size of the header 2, as well as permitting the substitution of larger or smaller traps for obtaining different operating pressure heads in conjunction with a single sized header.

It will be apparent from the above disclosure that I have provided a heat transfer element having means for creating a uni-directional steam ow, which device is comparable in size to average convector type heat transfer `elements not embodying such feature, as contrasted with previous devices for producing such results.

Having thus described my invention, it is obvious that various immaterial modifications may be made in the same Without departing from the spirit oi my invention; hence, I do not wish to be understood as limiting myself to the exact form, construction, arrangement, and combination of parts herein shown andv described or uses mentioned.

What I claimas new and desire Letters Patent is:

1. A heat transfer element. comprising in combination an inlet header having a steam inlet connection at its lower end, adapted to be connected to a steam supply pipe, said header having a vented water and air chamber positioned above and substantially axially aligned with said steam inlet connection, a heat transfer structure including a fluid passage having an inlet and an outlet therein connected to said header with said inlet operatively communicating with said steam inlet connection vand said outlet operatively communicating with said chamber, and a tubular trap member positioned in said inlet connection, said trap member extending down from said inlet header into the steam supply pipe and communicating with the water and air chamber and having its discharge end opening to said'steam inlet connection.

2. A heat transfer element comprising in combination an inlet header having a steam inlet connection at its lower end adapted to be connected to a steam supply pipe, said header having a vented water and air chamber positioned above said steam inlet connection, a heat transfer structure including a fluid passage having an inlet and an outlet therein connected to said header with said inlet operatively communicating with said steam inlet connection and said outlet operatively communicating with said chamber, and a tubular trap member extending down from and communicating with the water and air chamber, said trap member having a substantially U-shaped water collecting portion positioned below the inlet header withits discharge end opening to said steam inlet connection.

3. A heat transfer element comprising in combination an inlet header having a steam inlet connection at its lower end, said header having a vented Water and air chamber positioned above said steam inlet connection, a heat transfer structure including a fluid passage having an inlet and an outlet therein connected to said header with said inlet operatively communicating with said steam inlet connection and said outlet operatively communicating with said chamber, and a tubular trap member extending down from and communicating with the water and air chamber, said trap member having a substantially to secure by u-shaped. water collecting portion withy itsA discharge end opening to said: steam inlet, said' tubular member extending below said inlet connection and adapted to be positioned in a steam supply pipe secured to said connection.

4. A. heat transfer element comprising in combination an inlet header having a steam inlet connection at its. lower end adapted to be connected to a steam supply' pipe, said header having, a vented water and air chamber positioned above: said steam inlet. connection, a heat transfer structureincluding a fluid passage having an inlet and an outlet therein connected to said header with said inlet operatively communicating with said steam inlet connection and said outlet operatively communicating with said chamber, and a tubepositioned below the inlet header and.v extending down. from and communicating with the water and air chamber, said tube having a reverse bend therein adjacent its lower end with the. mouth thereof openingV to said steam inlet.

5. A heat 'transfer element comprisingy in combination an inlet` header having a. steam inlet connection at its, lower end, said headerl having a vented waterand air chamber positioned above said steam inlet connection, a heat transfer structureincluding a fluid passage having an inlet and an outlet tlie1ein,connected to said header with said inlet operatively communicating with said steam inlet connection and said outlet operatively communicating with said chamber, and a tubeextending down from and communicating with the water and air chamber, said tube having a reverse bend therein adjacentv its lowel` end. with the mouth thereof opening to said steam inlet, said reverse bend being positioned below said connection and adapted to be positioned. in a steam supply pipe secured to said connection. d v Y A 6. A heat transfer element comprising in combination an inletrheader having a steam inlet :onnection` at its lower end, said header having a vented water and air chamber positioned above said steam inlet connection, a heat transfer structure Aincluding a fluid passage having an inlet and an outlet therein connected to said header with said inlet operatively communicating with said connection and said outlet operatively communicating with said chamber, and a tubeextending Vrdown from and communicating with the water and air chamber, said tube being closed at its lower end and `rhaving a tubular trap member of greater diameter than said tube secured to and surrounding the lower end of said tube, the latter-*having anopening therein adjacent its lowerend communicating with the interior of said trap member. v

7. A heat transfer element comprising in cornbination an inlet header having a steam inlet connection at. its lower end, said header having avented water and air chamber positioned above said steam inlet connection, a heat transfei structure including a fluid passage having an inlet and an outlet therein connected to said header with said inlet operatively communicating with said. connection and said outlet operatively communicating with said chamber, and a tube extending down from and communicating with the water and air chamber, said tube being closed at. its lower end and having a tubular trap member of greater diameter than said tube secured to and surroundingthe lower rend of said tube, the latter having an opening `therein adjacent its lower end communicating 'with the interior of said trap member, said tubev extending below said steam inletA connection with said trap member adapted to be positioned in a. steam supply pipe secured to said connection.

8. A heat transfer element comprising in combination an inlet header having a steam supply pipe connection at its lower end, said header having a water and air chamber positioned above Vand substantially axially aligned with said pipe connection, said header having a bore substantially axially aligned with said chamber and' pipe connection adapted to operatively receive means for connecting an air release valve thereto, a heat transfer structure comprising a plurality of tubes, each secured at one of their respective ends to said inlet header, one of said tubes communicating with said water and air chamber, and another of said tubes communieating with said steam supply connection, a second header secured to and operatively connecting the opposite ends of said tubes, a plurality of iin elements carried by said tubes, and a tubular member extending down from :and communicating with the water and air chamber, said member having a reverse bend therein adjacent its lower end with the mouth thereof opening to said pipe connection, said reverse bend 'being po-V sitioned below said connection and adapted to berpositioned in a steam supply pipe secured to said connection.

9. A heat transfer element comprising in combination an inlet header having a steam supply pipe connection at its lower end, said header having a water and air chamber positioned above and substantially axially aligned with said pipe connection, said header having a bore substantially axially aligned with said chamber and pipe connection adapted to operatively receive means for connecting` an air release valve thereto, a heat transfer structure comprising a plurality of tubes, each secured at one of their respective ends to said inlet header, one of said tubes communicating with said water and air chamber, and another of said tubes communicating with said steam supply connection, a second header secured to and operatively connecting the opposite ends of said tubes, a plurality of iin elements carried by said tubes, and a tube extending down from and communicating with the water and air chamber, said tube being closed at its lower end and having a tubular trap member of greater diameter than said tube secured to and surrounding the lower end of said tube, the latter having 'i an opening therein adjacent its lower end communicating with the interior of said trap member, said tube extending below said steam inlet connection with said trap member adapted to be positioned in a steam supply pipe secured to said connection.

l0. A heat transfer element comprising in combination an inlet header having a steam supply pipe connection at its lower end, said header having a water and air chamber positioned above and substantially axially aligned with said pipe connection, said header having a bore substantially axially aligned with said chamber and pipe connection adapted to operatively receive means for connecting an air release valve thereto, a heat transfer structure comprising a plurality of tubes, each secured at one of their respective ends' to said inlet header, one of said tubes communicating with said .water and air chamben and another of said tubes communicating with said steam supply connection, a second header secured to andl operatively connecting theopposite ends. of. said' tubes, apluralityof fin elements carried by said tubes, and a tubular trap member extending down from and communicating with the water and air chamber, said trap member having a substantially ueshaped water collecting portion with its discharge end opening to said steam inlet, said tubular member extending below said inlet connection and adapted to be positioned in a steam supply pipe secured to said Vconnection.`

1I. A heat transfer element adapted to be connected to a steam supply pipe and comprising in combination an inlet header having a steam supply pipe connection at its lower end, said header having a water and air chamber positioned above and substantially axially aligned with said pipe connection, said header having a bore substantially axially aligned with said chamber and pipe connection adapted to operatively receive means forconnecting an air release valve thereto, a heat transfer structure comprising a plurality of tubes, each secured at onev of their respective ends to said inlet header, one of said tubes communicating with said water and air chamber, and another of said tubes communicating with said steam supply connection, a second header secured to and operatively connecting the opposite ends of said tubes, a plurality of fin elements carried by said tubes, and a tubular trap member extending down from and communicating with the water and air chamber, said trap member having a water collecting portion adjacent its lower end, Vthe latter having a discharge opening to said steam inlet, the lower end of said tubular member extending below said inlet connection and adapted to be positioned in the steam supply pipe secured to said connection.

12. In a heat transfer element for single pipe steam systems, a header member, a partition wall positioned in said header member and dividing the same into a steam inlet chamber and an adjacent air and condensate chamber, air venting means operatively communicating with said last-mentioned chamber and the exterior, a tubular extension positioned below and carried by said header communicating with said steam inlet chamber and adapted to be connected to a steam supply pipe, a pair of tubes operatively connected adjacent one of their corresponding ends to form a continuous passageway from the free end of one of said tubes to the free end of the other of said tubes, the free ends of said tubes being connected to the header structure, with such end of one of said tubes communicating with the steam inlet chamber, and the corresponding end of the other tube communicating with said air and condensate chamber, and a tubular trap member connected at its upper end to said header and extending downwardly into said extension, said trap member having a reversely curved passageway therein communicating at its upper end with said condensate chamber, and at its opposite end with the extension interior, said last-mentioned end of the passageway being positioned above an intermediate portion of the member, the latter portion being adapted to collect condensate, condensate so collected in said intermediate `portion opposing the passage of steam through said trap member into said air and condensate chamber.

13. In a heat transfer element for single pipe steam systems, a header member, a partition wall positioned in said header member and dividing' the same into a steam inlet chamberand Yan adjacent air and condensate chamber, air venting means yoperativelycommunicating with said lasts mentioned .chamber and the exterior, a ltubular extension positioned below and carried by said header communicating with said steam inlet chamber and adapted to be connected to a steam supply pipe, a pair of tubes operatively connected adjacent one of their corresponding ends to form a continuous passageway from the free end of one of said tubes to the free end of the other of said tubes, the free ends of said tubes being connected to the header structure, with such end of one of said tubes communicating with the steam inlet chamber, and the corresponding end of the other tube communicating with said air and condensate chamber, and a tubular trap member, including a tube, connected at its upper end to said header and extending downwardly into said extension, and communicating at its upper end with said condensate chamber, and a cup-shaped tubular member of greater diameter secured to and closing the lower end thereof, said tube also having an opening adjacent the lower end thereof communicating with the interior of said cupshaped member, the latter member being adapted to collect condensate, condensate so collected in said cup-shaped member opposing the passage of steam through said trap member into said air and condensate chamber.

14. In a heat transfer element for single pipe steam systems, a header member, a partition wall positioned in said header member and dividing the same into a steam inlet chamber and an adjacent air and condensate chamber, air Venting means operatively communicating with said last-mentioned chamber and the exterior, a tubular extension positioned below and carried by said header communicating with said steam inlet chamber and adapted to be yconnected to a steam supply pipe, a pair of tubes operatively connected adjacent one of their corresponding ends to form a continuous passageway from the free end of one of said tubes to the free end of the other of said tubesfthe free ends of said tubes being connected to the header structure, with such end of one of said tubes communicating with the steam inlet chamber, and the corresponding end of the other tube communicating with said air and condensate chamber, and a tubular trap member comprising a tube connected at its upper end to and communicating with said header and extending downwardly into said extension, said tube having a reversebend therein adjacent its lower end with the mouth thereof opening into said extension interior, the reverse bend portion being adapted to collect condensate, condensate so collected in said portion opposing the passage of steam through said trap member into said air and condensate chamber. BENJAMIN SPIETH.

REFERENCES CITED The following references are .of record in the le of this patent:

UNITED STATES vPATENTS Number Name Date 286,780 Clark Oct. 16, 1883 499,231 Kaeferle 1 June 13, 1893 933,869 Wilson Sept. 14, 1909 1,216,348 Murphy Feb. 20, 191'?` 2,056,263 Ehrlich Oct. 6, 1936 2,366,746 Miller Jan. 9, 1945 FOREIGN PATENTS- Number Country Date 116,732 Australia Apr. 1, 1943 

